He grew up in a patriotic family, and his mother often took him and his brother to the grave of her grandfather Stanisław Żółkiewski, Grand Hetman of the Crown, who was killed in the battle of Cecora in 1620.

Zofia Teofila Daniłłowicz taught her sons the inscription upon their great-grandfather's grave: "O quam dulce et decorum est pro patria mori!"

[5] In 1645 Jakub Sobieski, father of Marek and John, prepared special instructions and a guidebook for his sons, who were about to go abroad.

[2] Then, as a head of a chorągiew husarska (military unit formed by Hussars) of 100 horse, the young starosta joined the army of Jeremi Wiśniowiecki.

Marching with Jan Odrzywolski, but without his own hussar banner, Sobieski and his retinue came to the field hetman Kalinowski's camp at Batoh on 31 May.

Marek Sobieski and Odrzywolski were assigned to command cavalry banners during the subsequent battle, and in that capacity they fought on 1 and 2 June.

[21] After the battle, the Cossacks paid the Tatars for possession of the prisoners, and killed the Polish captives in retaliation for Chmielnicki's defeat at Berestechko.

[23] Sobieski's mother returned his body home,[2] and to commemorate her fallen son she founded the Church of the Assumption of Mary in Żółkiew, which was built between 1653 and 1655.

[2][19] Sobieski was portrayed by Henryk Sienkiewicz in With Fire and Sword (1884), Antoni Euzebiusz Balicki in Z żaka król (1936) and Jacek Komuda in novel Bohun (2006).